Safety-guard for power-presses.



1. WRIGHT. SAFETY GUARD FOR POWER PRESSES.

APPLICATION FILED DEC. 8. I914- Paten'ted Oct. 31, 1916.

In: Howl's Plrrns ca. ruomuma. \usumsmn. n. c

JAMES WEIGHT, 015 HAMILTON,

ONTARIO, CANADA, ASSIGNOR 0F THREE-EIGHTHS TO WILLIAM S. STACEY, 0F HAMILTON, CANADA.

SAFETY-GUARD FOR POWER-PRESSES.

Specification of Letters Patent.

Patented Oct. 31, 1916.

Application filed December 8, 1914. Serial No. 876,078.

To all whom it may concern:

Be it known that I, JAMES WRIGHT, a citizen of the Dominion of Canada, residing at Hamilton, in the county of Wentworth and Province of Ontario, Canada, have invented certain new and useful Improvements in Safety-Guards for Power-Presses, of which the following is aspecification.

This invention relates to safety guards for power presses of the type in which the punch or plunger of the press is prevented from making its effective movement if the guard encounters an obstruction such as the hand of the operator or any object exceeding ap- 15v proximately one-eighth of an inch 111 thickness.

The object of the present invention is to provide an improved and simplified structure of the character above set forth in which the guard is caused to move up and down in unison with, but somewhat in advance of the press plunger together with means for automatically releasing the clutch to stop the effective movement of the plunger if, as before stated, an obstruction is encountered by the guard.

Further objects and advantages of the invention will be set forth in the detailed description which now follows.

In the accompanying drawing, Figure 1 is aside elevation of a power press having the invention applied thereto. Fig. 2 is a detailed view of a portion of the opposite side of said press, and Fig. 3 is a detailed perspective view of the guard and its associated elements.

Like numerals designate corresponding parts in all of the figures of the drawing.

Referring to the drawing the numeral 5 designates a power press of the usual and well known construction and 6 the plunger thereof.

7 is the main shaft of the press and the driving wheel 8 is indicated by dotted lines. The usual clutch indicated at 9 serves to connect the driving wheel to the power shaft in the usual way.

10 designates the dog of the clutch and 11 the latch. This latch is pivoted at 12 to the press frame. An operating rod 13 extends from the latch to the treadle 14. These parts are of the usual construction and are believed to require no further description except that it may be stated that when the the treadle the dog is released to permit the clutch to clutch the shaft 7 to the driving wheel in the usual and well. known way. It is apparent therefore that if any other object corresponding to latch 11 be interposed in the path of the dog the clutch will be released and the efiective movement of the plunger prevented. To accomplish this, when the guard strikes an obstruction, such as the hand of the operator the mechanism shown in Fig. 3 is provided. Referring to Figs. 1 and 3 it will be seen that a rock shaft 15 is journaled in bearing brackets 16 mounted upon the upper rear part of the press frame. Arms 17 and 18 are carried by the rock shaft and project forwardly therefrom and the arm 18 carries a depending bracket 19 that supports an anti-friction roll :20. This roll is engaged by a cam 21 thatis secured by screws 22 to a collar 23 of shaft 7.

A guard 24 is secured to blocks 25 carried by depending rods 26. The upper ends of these rods pass through blocks 27 pivotally mounted upon the outer ends of the arms 17 and 18 and are adjustably held therein by set screws 28. It is apparent therefore that an up and down movement is imparted to the guard 24 from the rock shaft through the action of the cam 21. This cam is so shaped as to cause the guard to move downwardly in advance of the plunger. A bearing bracket 29 is rigidly affixed to the arm 17 and has pivoted thereto at 30 a block 31 that carries an arm 32. This arm 32 passes through the guide bracket 33 which is fixed to the arm 17. The arm 32 has an offset U-shaped portion 34: through the rear, leg 35 of which a set screw 36 is threaded. This set screw is provided with a lock nut 37. The adjustment of this screw determines the thickness required in an obstruction before said obstruction will act to prevent the movement of the punch or plunger. Lying within the ofiset portion 3st of arm 32 is the square head 38 of a rod 39. 'This rod passes through a bracket 40 that is pivotally mounted upon. one of the bearing brackets 16. A lower offset end of this rod is disposed in a slot 41 of a stop dog 42, said dog being pivoted for horizontal movement at *3. (See Figs. 1 and 3).

It is believed that the operation ofth e device will be apparent without further description but to make the operation of the invention entirely clear it may be stated that when no obstruction is encountered, and the guard moves downwardly its full travel the end of screw 36 at the termination of such downward movement or at nearly the termination thereof contacts with the-head 38 of rod 39 and moves said head forwardly. lliis moves the lower offset end of said rod rearwardly and the slot 41 is disposed at such an angle that the lower end of the rod is caused to rock the dog as upon its pivot to throw the front end of said dog away from the press frame and out of the path of movement of the clutch dog. If upon the other hand, the guard strikes an obstruction and is prevented from completing its full downward travel, the movement described is not imparted to rod 39 and consequently the dog remains in press stopping position. Upon the return or upward movement of the guard the front side of the U shaped portion 34 contacts with head 38 to restore the dog to press stopping position. It is to be noted that the normal position of the dog is one in which the operation of the press is prevented and that said dog is moved from such position only when the guard makes its complete stroke. It is to be understood that the invention is not limited to the precise construction embodied in the drawings, but includes within its purview such changes as come within the spirit of the appended claims. 7

Having described my invention what I claim is:

1. In a device of the character described, the combination with a press having a main driving shaft, of a rock shaft horizontally journaled upon the press frame at the rear thereof, forwardly projecting arms carried by said rock shaft, a guard supported from the free ends of said arms, means carried by the main shaft of the press for imparting movement to one of said arms, a clutch releasing dog, a pivoted lever for moving said dog and means supported from one of said arms having lost motion engagement with said lever.

2. In a device of the character described, the combination with a press having a main driving shaft, of a rock shaft horizontally journaled upon the press frame at the rear thereof, forwardly projecting arms carried by said rock shaft, a guard supported from the free ends of said arms, means carried by the main shaft of the press for imparting movement to one of said arms, a clutch releasing dog, a pivoted lever for moving said dog and adjustable means supported from one of said arms having lost motion engagementwith said lever.

3. In a device of the character described, the combination with a press having a-main driving shaft, of a rock shaft journaled thereon, arms projecting forwardly from said rock shaft, a guard supported from the free ends of said arms, means for imparting movement to the rock shaft from the main shaft, a verticallydisposed pivoted lever, a dog actuated by said lever and an arm supported from one of the first named arms and having an offset portion in which the upper end of said lever lies and with which said lever has lost motion engagement.

i. In a device of the character described, the combination with a press having a main driving shaft, of a rock shaft journaled thereon, arms projecting forwardly from said rock shaft, a guard supported from the free ends of said arms, means for imparting movement to the rock shaft from the mainshaft, a vertically disposed pivoted lever, a dog actuated by said lever and an arm supported from one of the first named arms and having an offset portion in which the upper end of said lever lies and with which said lever has lost motion engagement, and an adjustable member carried by the last named arm for engaging the head of the pivoted lever. in a safety guard for power presses the combination with a press comprising a driving member and a driven member, of a manually controlled latch which when actuated causes the driving and driven members to be connected, a press stopping latch normally lying in press stopping position, a guard, means for automatically moving the guard to and from protective position, and means operable only when the guard completes its movement to protective position for moving said press stopping latch out of press stopping position.

In a safety guard for power presses the combination with a press comprising a driving and a driven member, of a manually controlled latch which when actuated causes the driving and driven members to be connected, a second latch disposed in spaced relation to the first named latch and which normally lies in press stopping position, a guard driven from the press mechanism and automatically moved thereby to and from protective position and means operable only when the guard completes its movement to protective position for moving said press stopping latch out of pressstopping position.

7. In a safety guard for power presses the combination with a press comprising a driving member and a driven member, of the manually controlled latch which when actuated causes the driving and driven members to be connected, an auxiliary latch arranged in spaced relation to the firstnamed latch, a guard, means for automatically moving the guard to and from protective position, andmeans. operable only when theguard completes its movement to protective position for actuating said auxiliary latch to permit completion of the press movement.

8. In a safety guard for power presses the combination with a press comprising a driven shaft and a punch actuated therefrom, of a driving member and clutch for clutching said driving member to said shaft, a manually operable latch for controlling said clutch, an auxiliary latch normally lying in position to release said clutch, a guard, means for automatically moving said guard to protective position and for accelerating the movement of the guard with relation to the punch so that the movement of the guard to protective position is accomplished upon the initial movement of the punch, and means operable only upon the completion of the movement of the guard to protective position for moving the last named latch out of clutchreleasing position.

9. In a device of the character described. the combination with a press comprising a driving member and a driven member, a clutch for connecting the driving and driven members, a manually operable latch for controlling said clutch, a second latch normally lying in clutch releasing position, a rock shaft journaled upon the press frame, swinging arms carried by said rock shaft, means for imparting oscillatory movement to the rock shaft from said driven member, a guard carried by said swinging arms and moved thereby to and from protective position and lost motion connections between Copies of this patent may be obtained for five cents each, by addressing the said rock shaft and said second latch for moving said latch out of clutch releasing position, only when the guard has completed its travel to protective position.

10. In a safety guard for power presses the combination with a press comprising a driven shaft and driving member for said shaft, a clutch for clutching said driving member to said shaft, a latch which restrains said clutch from clutching action until said latch is actuated, a second latch normally lying in position to engage and release said clutch, swingingly mounted guard carrying members, means actuated from the driven member of the press for imparting swinging movement to said guard carrying members and a member engaging said second latch and with which said swingingly mounted members have lost motion engagement.

11. In a safety guard for power presses the combination with a press controlled by a clutch of a clutch releasing mechanism normally lying in clutch releasing position, a guard, and means for automatically moving said clutch releasing mechanism out of clutch releasing position only when the guard is moved to protective position.

In testimony whereof I aflix my signature in presence of two witnesses.

JAMES WRIGHT.

Witnesses W. S. STACEY,

E. J. PUSHINSKY.

Commissioner of latents,

Washington, I). G.

manually operable 

